Polarized relay switch



N0V- 7, 19335 E. M. AsHwoRTH x-:r AL 1,933,649

POLARI ZED RELAY SWITCH Filed Dec. 17, 1931 +A Al Patented Nov. 7, 1933UNITED STATES PoLARlzED RELAY SWITCH Edward M. Ashworth and Frank F;Ambuhl, To-

ronto, Ontario, Canada, assignors to Toronto Electric Commissions,Toronto, Ontario, Canada Application December 17,1931

Serial No. 581,658

4 Claims.

The principal objects of the invention are to provide a relay switchwhich may be operated by ank extremely small current so that aconsiderable number vof such devices may be connected to 5 a commonsource of power to be operated simultaneously.-

A further important object is to devise a relay of the polarized typehaving a strong and reliable operating movement to effect the operationof a circuit making and breaking device, and which may be manufacturedat a comparatively low cost. f

The principal feature of the invention'consists in the novelconstruction of aimagnetic device 15 whereby a moveable switch operatingelement is arranged in operating association with a permanent magnet andan electro-magnet, the latter being adapted to eiect an increase inthevmagnetic flux of either pole of the magnet to cause the operation ofthe armature.

In the drawing, Figure lis an elevational diagrammatical view of astructure adapted for carrying this invention into eiect.

Figure 2 is a side elevational View of the device illustrated in Figure1.

Figure 3 is an elevational view of the device from the opposite side tothe view illustrated in Figure l and showing the switch contacts.

In the operation of electric signs, water heating devices and otherelectrical operating appliances it is frequently desirable that suchdevices be controlled from some central point.

Numerous forms of distant control apparatus for accomplishing thisresult are known but they are both expensive to construct and requireconsiderable current to operate and are therefore difficult to maintainin operating service as well as being expensive.

According to the present invention the device illustrated in Figure 1consists of a permanent U-shaped steel magnet 1 upon which is arranged acentral pole or core 2 of soft steel or iron which is rigidly securedthereto, as here shown, by a screw 3 which also connects the magnet 1 toa base 4.

A magnet coil 5 encircles the core 2.

A yoke, preferably formed of a pair of plates 6, secured to end blocks'7 is clamped across the ends of the U magnet 1 and a spindle 8 isrotatably mounted centrally of `said yoke.

An armature 9 is rigidly secured to the spindle between the side plates6 of the yoke and it is provided with curved ends 10 concentric with thespindle 8k and these ends are arranged to 1 swing in close associationwith the similarly curved surfaces of the ends of the magnet l on thepivot of the armature.

The armature is also provided with a centrally arranged concentricportion l2jinidway of its length adapted to swing in close associationwith @0 the similarly curved end13 of the soit iron core 2.

A plate 14 preferably comprising a strip of steel is secured to theupper side of the armature and is provided with copper or other suitablenonmagnetic buffer pieces 15.

The'magnet ycoil 5 is here shown connected to a `two-Wire directVcurrent source of supply 16'and is controlled by the use of a doublethrow reversing switch 17, by means of which the polarity of the currentflowing throughthe coil may be changed. AIt may be found desirable tooperate this device on a single wire control, which on account of thelow rcurrent value, may be utilized with a grounded circuit.

When the relay coil is energized with polarity, as illustrated in Figure1, and, assuming the polesof the magnet l with a polarity as indicated,the magnetism or lines of force will be caused to flow inY the samedirection in the centre core and the right hand plus pole A and in theopposite or minus direction in the left hand minus pole B. The magneticflux in the pole B is approximately equal to the sum of the fluxes inthe centre pole and the pole A, thereby causing the armature to bepulled down toward the pole B until the over-hanging end of the flatsteel plate or strip 14 engages the top of the armature coming intomechanical contact with the end of the pole B. The armature is then heldin this position by virtue of the magnetic flux of the permanent pole Buntil the polarity of the operating coil is reversed,

' causing the armature to be pulled down on the side of the pole A. Thecopper bands 15 arranged on the ends of the steel strip or plate 14 ofthe magnet prevent the relay sticking in either one position or theother, and the presence of the overhanging steel strip 14 assistsmaterially in the operation of the armature from one side to the otherand tends to maintain the position of the armature after it has operateduntil the polarity of the operating coil is again changed. Mounted onthe spindle 8 is a disc 18 upon the outer face of which are secured twopairs of contact plates 19 and 20. These plates are 105 separated fromeach other and one of the pair of plates 19 is connected to the oppositeone of the pair ofy plates 20 by a cross connecting bar 21 arranged onthe back of the disc.

A contact block 22 is secured to the base 4 110 and carries the contacts23 and 24 connected to the coil 5. It also carries a pair of springcontact fingers 26 and 27 arranged one at each end and extendingvertically upward to engage the contact plates 19 and 20 of the disc 18.

The upper ends of these contact fingers 26 and 27 are preferablyprovided with suitable brushes to ensure ease and smoothness ofoperation.

Circuit contacts 28 and 29 are arranged on the brushes at the base andare connected to suitable service wires connecting with an operatingmechanism which it is desired to control.

It will be seen that when the current is directed in accordance with aselected polarity through the coil l, the armature may be manipulated tobe moved to either one side or the other and thereby move intoengagement with the brushes of the finger contacts a plate forming aclosed connection between said ngers so that an operating circuit willbe closed, or when the polarity of the control circuit is altered thearmature will be operated to rotate the spindle and disc 18 carriedthereby to open the operating circuit.

A device such as described will operate on an extremely small currentwhich may be defined as measured in milliamperes, consequently a greatnumber of these relay devices maybe operated from a single circuit. Thisenables electrical power companies to sell current on ofi peak loads forspecial purposes, such as operating electric water heaters and otherdevices which may be utilized to advantage with intermittent currentsupply and by the use of a low current, or a normal amount of currentover a supply system an entire block of relay devices may be operated.

What we claim as our invention is:-

l. A polarized relay comprisiniT a permanent U-magnet, an armaturerotatably mountedbetween the poles of said magnet and having aprotuberance intermediate of its length presenting a surface concentricwith the armature axis,

and an electro-magnet mounted within said U- magnet and having a coreterminating in a curved surface concentric with the concentric surfaceof the protuberance oi the armature in close influential relationthereto, said electromagnet being adapted to be selectively energized toeffect rotation of the armature in either direction.

2. A polarized relay comprising a permanent U-magnet, a bar armatureextending between the poles of said magnet and having a transverse axistherebetween, an electro-magnet mounted within the U-magnet and adaptedto be selectively energized to eiiect rotation of the bar armature ineither direction on its pivot, and a strip of metal extendinglongitudinally of the bar armature and secured thereto and having itsends extending beyond the ends of the armature and overhanging the poleends of the U- magnet in co-operative relation therewith.

3. A polarized relay comprising a U-shaped permanent magnet, anelectro-magnet mounted between the arms of said permanent magnet poles,a spindle journalled centrally between the poles of the magnet, anarmature rigidly mounted intermediate of its length on said spindlehaving its respective ends disposed adjacent to the poles of thepermanent magnet and having a central portion disposed in inuentialrelation to the end of the core of the electro-magnet, saidelectro-magnet being adapted to be selectively energized to eiiect therotation of the armature in either direction, and stop means forarresting the armature after movement in either direction.

predetermined 4. A polarized relay as claimed in claim 2 in n which saidstrip of metal is magnetic and carries non-magnetic buffer pieces forstop contact with the pole ends of the U-magnet to prevent sticking ofthe armature.

EDWARD INI. ASHWORTH. FRANK F. ANIBUHL,

